[llvm] [KnownFPClass] Infer signs of finite nonzero fdiv results (PR #214912)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 139501 tests passed
* 3660 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.Transforms/InstCombine/fptoui-of-fdiv.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
c:\_work\llvm-project\llvm-project\build\bin\opt.exe < C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstCombine\fptoui-of-fdiv.ll -passes=instcombine -S | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstCombine\fptoui-of-fdiv.ll
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -passes=instcombine -S
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstCombine\fptoui-of-fdiv.ll'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstCombine\fptoui-of-fdiv.ll:113:15: error: CHECK-NEXT: expected string not found in input
# | ; CHECK-NEXT: [[A:%.*]] = uitofp i32 [[X]] to double
# |               ^
# | <stdin>:49:35: note: scanning from here
# | define i32 @zero_divisor(i32 %x) {
# |                                   ^
# | <stdin>:49:35: note: with "X" equal to "%x"
# | define i32 @zero_divisor(i32 %x) {
# |                                   ^
# | <stdin>:49:35: note: pattern attempts to capture variables: "A"
# | define i32 @zero_divisor(i32 %x) {
# |                                   ^
# | <stdin>:50:2: note: possible intended match here
# |  ret i32 0
# |  ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\Transforms\InstCombine\fptoui-of-fdiv.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |             .
# |             .
# |             .
# |            44:  %d = fdiv double %a, 2.500000e+00 
# |            45:  %r = fptoui double %d to i32 
# |            46:  ret i32 %r 
# |            47: } 
# |            48:  
# |            49: define i32 @zero_divisor(i32 %x) { 
# | next:113'0                                      {   search range start (exclusive)
# | next:113'1                                          error: no match found in search range
# | next:113'2                                          with "X" equal to "%x"
# | next:113'3                                          pattern attempts to capture variables: "A"
# |            50:  ret i32 0 
# | next:113'4      ?           possible intended match
# |            51: } 
# |            52:  
# |            53: define i64 @width_mismatch(i32 %x) { 
# | next:113'5                                }           search range end (exclusive)
# |            54:  %a = uitofp i32 %x to double 
# |            55:  %d = fdiv double %a, 7.000000e+00 
# |            56:  %r = fptoui double %d to i64 
# |            57:  ret i64 %r 
# |            58: } 
# |             .
# |             .
# |             .
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/214912